An unspecified security incident caused the personal information of current and former employees to be exposed. No classified data was lost.

UPDATE (08/30/2013): An August 29 memo revealed that the system that was hacked was called DOEInfo. A total of 2,539 current employees and 3,172 former employees were affected. Names, Social Security numbers, and dates of birth were exposed.

UPDATE (09/03/2013): Approximately 53,000 current and former federal employees, employee dependents and contractors had their information exposed. The incident occurred in July of 2013.

UPDATE (10/22/2013): The Department of Energy revised the number of affected current and former employees to 104,000.

UPDATE (12/13/2013): Up to 150,000 employees may have been affected.

UPDATE (12/17/2013): A federal audit revealed that the Department of Energy had received warnings about the security of its information systems, yet failed to act.